Kill or cure? Atkins diet debated in diabetes
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Kill or cure? Atkins diet debated in diabetes
OCTOBER 18, 2010 | Lisa Nainggolan
Stockholm, Sweden - The fact that lifestyle interventions
can often do better than drugs at controlling type 2 diabetes
is recognized by many in the field, but implementation of
this approach is hampered by the fact that it is difficult to
get busy general physicians to actively encourage lifestyle
change or to get affected individuals to alter lifelong habits.
But one nutrition expert believes he has the answer: the
Atkins diet. Dr Eric C Westman (Duke University, Durham,
NC) admittedly has vested interests in promoting this
approach—he is the coauthor of the latest Atkins book and
receives honoraria from Atkins Nutritionals—but argues that
he values his reputation above all else and that his aim is to
convince people that the science exists to back his claims.
At last month's European Association for the Study of
Diabetes (EASD) conference, Westman gave a lecture on the
subject of low-carb diets. In contrast to most of the research
that is presented at diabetes meetings—"98% of which
relates to pharmaceuticals," he says—he set out to show how low-carb diets can be "more powerful"
than drugs to treat type 2 diabetes.
"I was trying to demystify what the diet meant and also show data on how you get control of the
diabetes and weight loss in one fell swoop," he explained to heartwire in an interview.
Westman acknowledges that the prime factor in the success of this approach is that people lose
weight; the Atkins diet, he says, makes this easy because people find it simple to follow and feel
satiated. But he also believes the low-carb approach has a benefit in addition to weight loss when it
comes to diabetes, explaining that "it's the excessive carbohydrate that causes the pressure toward
diabetes." Indeed, years before medications were available to treat diabetes, a low-carbohydrate diet
was used as the primary treatment of diabetes mellitus, he told meeting attendees.
But although other nutrition experts whom heartwire spoke to agree that lifestyle interventions have a
key role to play in diabetes, they say that Atkins is unsuitable for diabetics: too restrictive for people to
stay on long term and potentially unsafe.
Science exists to take Atkins seriously
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Westman says the mainstream belief "is that high-fat diets are harmful, so
physicians are not going to recommend them." The new Atkins book, he says,
was specifically designed "to allay the fears of doctors, to have a book with all
the science in the back."
At the EASD meeting, Westman presented data from a number of trials and
meta-analyses illustrating the effectiveness of low-carb diets on obesity and
metabolic-syndrome parameters, including the DIRECT trial, and a recent
meta-analysis [1] showing that low-carb/high-protein diets are as effective, if
not more so, as low-fat diets in reducing weight and cardiovascular disease risk
up to one year.
The more limited research on low-carbohydrate diets in type 2 diabetes include a
pilot study [2] and a randomized controlled UK trial in just over 100 subjects [3],
Eric C Westman [Source:
showing a trend to a lower HbA in those on the low-carb diet. In his own "pilot Duke University]
1c
randomized" study [4], Westman found that a low-carb diet (20 g per day)
significantly reduced HbA1c by threefold compared with the low-glycemic-index diet (100g
carbohydrate per day; phttp://www.theheart.org/article/1137677/print.do
Eckel believes a much better option for short-term weight loss is the South Beach
diet. "If someone wants to get into a bathing suit for a reunion or something and
needs to lose weight quickly, sure go low-carb, and you'll probably lose weight
more quickly, but I would be more comfortable with South Beach, which has fats
that you and I would consider 'better,' such as more plant-based lipids. Plus the
saturated-fat content is only around 10% of total calories."
This advice, says Eckel, applies equally to nondiabetics as well as to diabetics
who want to lose weight and improve glycemia over a short interval of time.
However, one of the problem with recommending the South Beach diet is that
"there are no data on it," Eckel acknowledges.
And he is keen to stress that neither he nor the AHA would recommend South
Beach long term as a diet for patients with diabetes. "If [sustained] weight loss is
Dr Robert Eckel needed, it needs to be a carefully constructed, evidence-based program of tough
love and frequent monitoring."
Dietician Stephanie A Dunbar, director of nutrition and medical
There are no long-term affairs for the ADA, says the major problem with making dietary
data comparing the recommendations for people with diabetes "is that there are no
different diets in diabetes long-term data comparing the different diets in diabetes
management. management."
The ADA does not recommend an Atkins-type diet in diabetics, she adds, noting that Westman has
taken the ADA position statement on low-carb diets "out of context," because it is meant to refer to
weight loss in people without diabetes, "where it is simply saying that there is some evidence that
low-carb and low-fat diets both work."
Diets for diabetics should reduce carbs, but not excessively
Dunbar does point, however, to some very recently published research on the
effects of different diets in diabetes and on incidence of diabetes.
The Look AHEAD data in patients with type 2 diabetes show that those who
followed an intensive lifestyle-intervention program lost weight, improved
fitness, and maintained these goals, with significant improvements in blood
pressure, glycemic control, and some lipid measures (although not LDL) over four
years, compared with a usual-care control group. In this study, the intensive-
lifestyle-intervention group had a calorie goal (1200-1800 kcal/d based on
initial weight), with less than 30% of total calories from fat (http://www.theheart.org/article/1137677/print.do
carbohydrates," Astrup says. This diet is "very effective at weight consistently across all the
control and reducing insulin resistance and inflammation. This research studies, it's very
composition makes the diet much easier to fit into an acceptable confusing.
food culture and gastronomy," he notes.
Dunbar says another problem when trying to compare and discuss these different diets is that
"low-carb is not defined consistently across all the research studies, it's very confusing." In some
studies, 150 g a day is considered low-carb, whereas Westman considers 20 g per day to be low-carb,
"so what you find is that a lot of the 'low-carb' research is more 'moderate carbohydrate,' " she says.
Is it the method of weight loss or the weight loss per se that matters?
At the EASD meeting, Westman outlined three case reports in which people he has treated dropped
weight and dramatically reduced their HbA , allowing them to come off medications. "If you want your
1c
patients to love you, improve their glucose; get them off insulin and injections. I'm afraid I'm
competing with endocrinologists in my area who are pushing those drugs."
However, whether people can ultimately come off medications as
If you want your patients opposed to just reducing the doses "depends on the underlying
to love you, improve their ability of the pancreas to secrete insulin," he says. "If the
glucose; get them off insulin and pancreas works fine, we can get people off meds, but if they've
injections. burned out their pancreas, they are going to need some sort of
supplement regardless of the weight loss."
But the fact that Westman is able to take patients off their diabetes medications is not rocket science,
Eckel says. He points out that anyone who can maintain a higher-carbohydrate-content diet, restricted
in fat and total calories, and can lose weight will also experience a reduction in the need for diabetes
medications. "This has been shown by many people over the years."
Westman admits that—other than his own small trial [4]—he can't say definitively that it's the method
of weight loss that is more important than the actual weight loss.
At the EASD meeting, he tried to explain why he believes low-carb diets are good for diabetics.
Starches such as bread and pasta raise serum glucose, but low-carb diets reduce the dietary
contribution to serum glucose, which then lowers insulin levels, he said. Although diabetics have fat
stores, they can't access them due to high insulin levels. Lowering insulin levels allows an individual to
use their stored body fat, prompting weight loss.
"It's my hunch that it's both—it's the weight loss, but how you do it gives you a little extra power," he
says. But he concedes "some of the vegan studies, which were higher in carbs, also have good effects."
The newly published substudy of the PREDIMED trial adds weight
to the theory that what people eat might be as important as the It's my hunch that it's
amount they eat: in this study, the researchers showed that by both—it's the weight loss,
changing the foods people ate, they could reduce the risk of but how you do it gives you a little
diabetes onset by half, without weight loss. extra power.
Dunbar says these new results with the Mediterranean diet "are very exciting. Since weight loss is so
difficult for people, I think this deserves some attention and hopefully further research."
She adds: "I don't think there is one particular diet that is going to work for every person. Our real
recommendation for people with diabetes is that they need to have an individualized approach to meal
planning, whether they need to go to 35%, 40%, or 45% of calories from carbohydrates, that needs to
be individualized." To illustrate this, she points to the vegan diets that even Westman concedes have
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good results, noting that these are often 75% carbohydrate: "Clearly, there is not one answer."
Can weight loss and diabetes control with Atkins be maintained?
Asked whether weight loss and diabetes control can be maintained long term with the Atkins diet,
Westman says the data from DIRECT show that the effects are sustained at least out to two years. "In
my clinical experience, the control will remain as long as people remain on the low-carb-lifestyle
approach," he said. "What we do teach people is to add back a small amount of carbohydrates for
variety's sake, but the improvement in diabetes remains as long as they stay away from
high-carbohydrate diets."
He says the key to the success of Atkins is the appetite
With these diets there is no suppression that is induced. "There's a myth that you have to be
suffering, no hunger and deprived when losing weight. But with these diets there is no
there is a feeling of satiety. suffering, no hunger, and there is a feeling of satiety." He says
one of his biggest problems is persuading people who are afraid
of fat in their diet to give the low-carb approach a go, "because they gravitate toward a low-fat diet,
and it doesn't work as well [for controlling diabetes]."
Eckel begs to differ, however, although he does concede that a low-carbohydrate diet is an effective
appetite suppressant. "Whether it is Atkins or South Beach, it tends to be an anorectic-type of
program; the ketone bodies that are generated by eating low carbs tend to have an appetite-
suppressant effect; he's correct there."
But Eckel argues that the very restrictive nature of Atkins with respect to carbohydrates makes it nigh
on impossible to maintain compliance in the long term. Astrup agrees: "Nobody wants to skip all carbs
for the rest of their lives."
Claims to improve HDL, but biology of HDL still poorly understood
And Eckel reiterated his concerns about long-term safety with Atkins. "Of course, the studies of weight
loss with Atkins short term are convincing, but we published a study recently [8] that showed that,
after six weeks on the Atkins diet, the fatty-acid burden is substantial, [as is] the rise in LDL
cholesterol. Atkins is atherogenic. I'm concerned about the overall content of saturated fat and its
impact on LDL cholesterol."
Dunbar says the ADA has concerns similar to Eckel's, although it
acknowledges a lack of evidence on the effects of specific fatty Atkins is atherogenic. I'm
acids on people with diabetes; hence, its recommendations are concerned about . . . its
for the time being "consistent with those for individuals with impact on LDL cholesterol.
cardiovascular disease."
But she notes that in its 2010 position statement, the ADA states that "saturated fat should behttp://www.theheart.org/article/1137677/print.do
But again, Eckel contests the importance of this. "This claim that Atkins preserves the HDL level" is
irrelevant, he says, since "the science is not advanced enough yet to say whether a rise in HDL is a
good thing. To make any conclusions on this is really premature."
Dunbar stresses: "We do not recommend an Atkins type low-carb diet because of the concerns about
the impact of that fat load on heart health."
Large outcomes trials needed with low-carb diets?
Westman says a long-term outcomes study comparing low-carb and low-fat diets is sorely needed;
such data do exist for the Mediterranean diet, he notes.
"Everyone talks about the Mediterranean diet, but the low-carb one looked just as good in the DIRECT
study. I'm an advocate for studying this kind of approach within mainstream medical research; it's
been avoided, and that's too bad. It needs to be given the same attention as other approaches," he
concludes.
But Eckel is vehemently opposed to any such outcomes study with Atkins, telling heartwire: "I feel that
would be an irresponsible trial."
Westman reports receiving honoraria from Atkins Nutritionals, being a coauthor of The New Atkins for a New You, and
a co-owner of Innovative Metabolic Solutions. Eckel reports no conflicts of interest. Astrup is a salaried author for Ude
& Hjemme and a salaried editor-in-chief of Obesity Reviews. He is also an advisor or member of an advisory board for
a number of food and pharmaceutical producers: Arla, European Almond Advisory Board, communications and
scientific advisory board of the Global Dairy Platform, 7TM Pharma, Novo, NeuroSearch, Basic Research, Merck, Johnson
& Johnson Pharmaceutical Research & Development, Reuters Insight, and Jennie Craig and recipient of honoraria as
speaker for a wide range of Danish and international concerns. He also has ownership, in accordance with the Danish
University regulations, of inventions and patents where he is coinventor. Astrup has bought shares in Mobile Fitness
and is an executive board member of Obesity International Trading (London), Beer Knowledge Institute
(Amsterdam), Global Dairy Platform (Chicago), and Nordic Food Lab (Copenhagen).
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Sources
1. Hession M, Rolland C, Kulkami U, Wise A, Broom J. Systematic review of randomized controlled trials of
low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev
2009; 10:36-50.
2. Boden G, Sargrad K, Homko C et al. Effect of a low-carbohydrate diet on appetite, blood glucose levels, and
insulin resistance in obese patients with type 2 diabetes. Ann Intern Med 2005; 142 (6): 403-411.
3. Daly ME, Paisey R, Paisey R, et al. Short-term effects of severe dietary carbohydrate-restriction advice in Type 2
diabetes—a randomized controlled trial. Diabet Med 2006; 23:15-20.
4. Westman EC, Yancy WS Jr, Mavropoulos JC, et al. The effect of a low-carbohydrate, ketogenic diet versus a
low-glycemic index diet on glycemic control in type 2 diabetes mellitus. Nutr Metab (Lond) 2008; 5:36.
5. American Diabetes Association. Standards of medical care in diabetes—2010. Diabetes Care 2010; 33 (suppl
1):S11-S61.
6. Fung TT, van Dam RM, Hankinson SE, et al. Low-carbohydrate diets and all-cause and specific mortality. Two
cohort studies. Ann Intern Med 2010; 153: 289-298.
7. Yancy WS Jr, Maciejewski ML, and Schulman KA. Animal, vegetable, or . . . clinical trial? Ann Intern Med 2010;
153:337-339.
8. Hernandez TL, Sutherland JP, Wolfe P, et al. Lack of suppression of circulating free fatty acids and
hypercholesterolemia during weight loss on a high-fat, low-carbohydrate diet. Am J Clin Nutr 2010;
91:578-585.
Related links
New PREDIMED data: Mediterranean diet halves incidence of new-onset diabetes
[Prevention > Prevention; Oct 15, 2010]
RENEW: Intense diet/exercise improves weight, CV risk factors, in severely obese
[Lipid/Metabolic > Lipid/Metabolic; Oct 11, 2010]
Free food, some oversight, and a plan: Popular commercial diet works in randomized trial
[Lipid/Metabolic > Lipid/Metabolic; Oct 11, 2010]
Look AHEAD in print: Lifestyle intervention improves CV risk factors in type 2 diabetes
[Lipid/Metabolic > Lipid/Metabolic; Sep 29, 2010]
Similar weight loss, HDL edge for low-carb vs low-fat in randomized diet study
[Lipid/Metabolic > Lipid/Metabolic; Aug 05, 2010]
Same weight loss, better BP with low-carb diet vs drug/diet combo
[Clinical cardiology > Clinical cardiology; Jan 25, 2010]
Low-carb diets hit the headlines again
[Prevention > Prevention; Dec 11, 2009]
Mediterranean diet might delay need for drugs in diabetes
[Lipid/Metabolic > Lipid/Metabolic; Sep 03, 2009]
"Eco-Atkins" plant-based, low-carb diet appears to lower cholesterol
[Lipid/Metabolic > Lipid/Metabolic; Jun 11, 2009]
Fewer calories=less weight, regardless of carb, fat, or protein content
[Prevention > Prevention; Feb 25, 2009]
Low-carb and Mediterranean diets beat low-fat for weight-loss, lipid changes at two years
7 of 8 11/9/10 11:18 AMhttp://www.theheart.org/article/1137677/print.do
[Lipid/Metabolic > Lipid/Metabolic; Jul 16, 2008]
Diet dilemma: Are cardiologists going loco for low-carb?
[heartwire > Features; Feb 24, 2004]
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